Bucket tooth for excavating equipment



March 11, 1969 L. w. CREAGER BUCKET TOOTH FOR EXCAVATING EQUIPMENT Filed Oct. 25. 1965 INVENTOR Lester W. Creoger ATTORNEYS United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE A readily replaceable tooth assembly for excavating buckets wherein the tooth portion is provided with a dovetail for slidable insertion into a complementary dovetail receiving groove formed in the converging ends of two angled base members whereby the whole assembly can be locked in place by a single weld.

This invention relates generally to earth digging equipment in the form of dippers, buckets, shovels, etc., and more specifically to a replaceable or easily removable tooth on such type of bucket or other similar earth digging device.

Many attempts in the past have been made to provide teeth that in one way or another, and after considerable wear, may be replaced. However, the difficulty has been that the teeth in such instances are generally locked in place by being made integrally with the bucket, or if intended to be removable, are locked in place in such fashion that easy removal is practically impossible. Thus Wedges, pins, rivets, etc., have all been employed to attain the objective of quick removal. As a matter of practice, however, and with use of such equipment, it has generally been found that replacement in the field is a practical impossibility. Also, as typical of past devices of this nature, if it is possible to remove and replace the teeth of a bucket, such involves a time consuming procedure.

The concept of the present invention contemplates the mere knocking out of the tooth, enabled by reason of the fact that only a small spot weld is employed to maintain the entire assembly in fixed position during operation of the involved equipment.

These disadvantages of prior designs have been obviated by the instant invention.

It is thus a primary object of the invention to provide a replaceable tooth arrangement for a dipper, bucket, dragline, backhoe, or like equipment, which facilitates removal thereof for replacement purposes, and enables the entire task to be completed within a matter of but a few minutes, in contrast to the time consuming procedures which are necessary with regard to known devices of this nature. Thus, the tooth of this invention can be secured in fifteen minutes or less by one spot of weld on each side thereof, in contrast to the well known types of casted points which often require from five to six hours to remove and weld or otherwise fix into place.

It is a further objective of the invention to provide a device of the described type which enables removal and replacement of teeth with a minimum amount of labor so that replacement can be easily effected in the field, without heavy equipment or other devices generally needed to accomplish the same purpose.

An additional object of the invention is to provide a replaceable tooth supported between removable protective blades, the latter also being subject to replacement with relative ease.

These and other objectives and advantage of the invention will be more readily understood by reference to the following more detailed description thereof, and reference to the several drawings in connection therewith, wherein:

3,431,664 Patented Mar. 11, 1969 FIGURE 1 is a perspective view of a general bucket form of arrangement wherein the teeth representing the invention are schematically illustrated as being mounted upon the forward plate of the dipper.

FIGURE 2 is a perspective view of the invention in exploded form, illustrating the dovetailed tooth separated from its grooved base support, and illustrating also one of the protective plates partially withdrawn from its normal operative position in contact with the replaceable tooth, and

FIGURE 3 is a side elevation view of the several elements of the combination as finally disposed to securely lock the tooth in operative position.

Referring more particularly to these figures, the tooth of the invention is generally indicated at 1, here shown positioned upon the front plate 6 of a usual shovel, bucket or other equivalent type of excavating equipment. The latter is mounted in usual fashion upon its carrying shaft 8 and the usual dragline interconnected through the common form of sheave 10, the latter in turn being interconnected to the swiveled yoke 12.

The details of the assembly are more clearly shown in FIGURE 2. Here two plates 15 and 16, angled with respect to each other, are provided. As indicated in this figure they are so angled with respect to each other the distance indicated at A, such angularity being maintained by an insert or shim 17, a triangular piece of complementary angularity. The angle A is, of course, here illustrated as an arbitrary one; in order to accommodate different types of equipment it may be increased or decreased, so long as the general construction of the combination which is here being described, is retained.

At any rate, each of the base plates 15 and 16 is dovetailed upon the outer face thereof as indicated at 18 and 20, such dovetails being adapted to receive in slidable fashion the tWo protective plates 22 and 24 respectively. Such protective plates are each grooved, as by dovetail grooves 26 and 28 in the lower plate 24, and grooves 30 and 31 in the upper plate 22. The said upper plate in this representation of the invention is indicated as being partially withdrawn from its normal, fixed position, for purposes of illustration of the manner by which it engages the dovetails 18 and 20. In order that each plate fit the side of the tooth against which it rests in fixed and operative position, each contacting edge of these protective blades is beveled, as at 23, at an angle complementary to the angle of the tooth formation against which it rests.

Each of the protective plates is also notched or grooved at its engaging end, as by grooves 35 and 38, these respective notches, together with the insert 17, forming a dovetail slot or groove adapted to receive the dovetail formed upon the inner end of the tooth formation, as will be described.

When these several elements of the combination are positioned as shown in FIGURE 2 they are prepared to accommodate the removable tooth, illustrated here in line with the groove just described, but withdrawn therefrom.

The removable tooth itself, also shown as a separate component in FIGURE 2 is provided with two forward material engaging edges 50 and 51, in this embodiment of the invention the surfaces of 50 and 51 being disposed approximately at right angles to each other, although the angularity here may also be varied to meet operative conditions, as required. At any rate, in this embodiment of the invention the tooth may be considered as of approximately square configuration, in cross section, having two rearward sides 52, which converge to meet and form an additional dovetail 55.

It is this dovetail 55, of course, which is adapted to engage in slidable fashion the dovetail groove formed in the members 22, 24 and and 16, and as provided by the grooves 35 and 38, heretofore described.

In assembly of the elements described with respect to FIGURE 2, the dovetail 55 of the tooth 1 is simply inserted in the angular configurations of the surfaces 35 and 38 so that each of the sides 57, 58 of the tooth are parallel or flush with the sides of the members 15, 16 and 22, 24. Each protective plate is then slid into place, this o eration being indicated in FIGURE 2, the plates finally being firmly positioned against surfaces 51 and 52 of the tooth as indicated in FIGURE 3.

It may be preferred to adjust the involved tolerances such that the protective plates are more or less press fitted in the sense that the respective grooves therein rather tightly accommodate the dovetails on the exterior surfaces of each of the base plates 15 and 16.

It will be noted, as shown in FIGURE 3, that the top surfaces of such protective plates cover all portions of the tooth except the forward, earth or material engaging portions 50 and 51. They are not only protective in this sense, but bearing tightly against the inner surface 52 of the tooth rigidly support the latter against undesirable movement.

Only a single weld, and more commonly a spot weld, is needed to maintain all these component parts in operative position, and as such are shown in FIGURE 3. Such weld is indicated at 60 where it engages not only the rear dovetail 55 of the tooth but also, each of the base plates 15 and 16, being overlapped, as shown at 60 (FIGURE 3) to achieve this objective. Hence, such single Weld locks in place the tooth 1, upper base plate 15, lower base plate 16, and the intermediate shim or angled base 17 which is interposed therebetween.

It may be desirable, particularly if the protective plates are not press fitted to maintain their position as shown in FIGURE 3, to extend the weld 60 to contact the outer plates 22 and 24; on the other hand, a small spot weld 62 at the end of each protective plate will also accomplish this same function.

In removal of the tooth it is simply necessary to strike one side of the same sharply so as to shear the weld 60 with the result that the tooth may be readily withdrawn from its corresponding groove, as indicated.

If the spot weld 60 overlaps sufliciently to contact the upper and lower plates 22 and 24 its resultant shearing by impact upon the tooth on the opposite side thereof will also release plates 22 and 24 so that they may be withdrawn to further facilitate removal of the replaceable tooth 1.

In any event, the invention represents the essence of simplicity insofar as a suitable tooth locking mechanism be concerned, and as represented by the single weld 60 of FIGURE 3. In contrast to the normal type of pin or integrally cast teeth for shovel, draglines, backhoes, and other excavating equipment, the instant invention provides a readily removable tooth requiring only a matter of minutes to replace.

The importance of ready replacement is not only emphasized by the resultant man-hour savings but by the further advantage that repairs of this nature can be accomplished in the field and at the working site, with little difficulty. Under usual arduous operating conditions the teeth of bucket type excavating equipment referred to in the foregoing wear out relatively quickly. When worn it is obvious that the eificiency of any heavy type excavating machine in present day use is greatly impaired.

It is evident that many modifications to this invention may be made. For example, and as indicated above, the angularity of the biting edges 50 and 51 of the tooth may be varied; the angularity A of the base plates and superimposed protective plates may also be varied within wide limits to suit the particular type of, e.g., bucket or dragline that may be encountered.

As to each type of such equipment, however, the described general example of the inventive combination will retain its same form and as here illustrated, the several component parts being designed to fit known makes of such equipment, and precast or fabricated to adapt the tooth assembly to heavy machinery of the type indicated of any particular make. In other words, all parts of the combination may be cast to manufacturers specifications to suit the particular design of bucket equipment which is involved.

As just indicated, many modifications and alterations may be made to the described invention without departing from the spirit thereof, the scope thereof to be limited only by the limitations asserted in the claims appended hereto.

I claim:

1. In a replaceable tooth assembly for excavating buckets, the combination comprising two angled base members joined at their intersection to form a dovetail receiving groove, each of said base members being provided with a half dovetail formation at the converging edge thereof whereby to form a dovetail receiving groove, an excavating tooth having a front material engaging surface and a rear dovetail formation of a dimension to engage said dovetail receiving groove, said material engaging surface being substantially right angular in formation, an angular shim positioned between said base members, said shim fixing the angularity between said base members and forming a part of said dovetail receiving groove, said rear dovetail formation being removably positioned in said groove with the sides of said tooth in alignment with the sides of said base members, said entire combination being adapted to be retained in fixed position by a single weld overlapping one of said tooth sides and adjacent sides of said base members.

2. The invention as defined in claim 1 wherein each of said base members is provided with at least one longitudinal dovetail upon the upper surface thereof, a protective plate for said tooth having a dovetail groove adapted to engage said longitudinal dovetail, the forward edge of said plate matching the configuration of said rear dovetail formation of said tooth, said protective plate being adapted to slide along said longitudinal dovetail to lock said plate against said tooth.

3. The invention as defined in claim 1 wherein a pair of dovetails is positioned on each outer surface of said base members, two protective plates having dovetail grooves are positioned to engage each of said pair of dovetails and to bear against said tooth, and said base members, tooth member and said plates all have approximately the same width.

References Cited UNITED STATES PATENTS 1,060,141 4/1913 Snyder.

1,174,331 3/1916 Mankins 37142 1,461,136 7/1923 Moore 37-142 2,896,345 7/1959 Peklay 37-142 3,082,555 3/1963 Hill 37-142 ABRAHAM G. STONE, Primary Examiner.

J. W. PETERSON, Assistant Examiner. 

